If my parents have a DIRECTV satellite, would I be able to watch their DirecTV if I download the DIRECTV stream app?

No, the DIRECTV Stream app doesn't grant access to content from DIRECTV satellite subscriptions. It's a separate service with distinct subscriptions and content libraries. To watch your parents' DIRECTV satellite service remotely, they'd need to enable "DIRECTV Everywhere" features and share their login credentials with you. Alternatively, they could explore options like adding extra receivers for additional TVs or upgrading to the Genie HD DVR for enhanced multi-room viewing capabilities.

[Edited by Moderator]